fix: real-time bg messages, join clears invite, richer seen-by, nicer badge (0.1.10/batch63)

1. Notifications/messages lagged when the desktop window was backgrounded —
   Electron throttles hidden renderers by default, stalling the chat WS's
   onmessage + timers. Set backgroundThrottling:false → real-time in the tray.
   (Transport is WebSocket; no Firebase needed.)
2. Joining a call via the header Join button left the Join/Decline invite popup
   on screen — enterMeeting now dismisses the invite (and stops the ring).
3. Seen-by is now "Message info": real contact DPs, a "Not seen yet" list for
   groups, and dark lettering (white-on-pastel initials were invisible).
4. App-icon unread badge: red→pink gradient pill with a white ring + shadow,
   drawn at 2x, instead of a flat red disc.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

desktop/main.js

@@ -198,6 +198,11 @@ function createWindow() {
       nodeIntegration: false,
       // Persist cookies/localStorage so the technician stays logged in between launches.
       partition: 'persist:bizconnect',
+      // Keep the renderer at full speed when the window is in the BACKGROUND/minimized. Electron
+      // throttles hidden windows by default, which stalled the chat WebSocket's onmessage + timers —
+      // so incoming messages and their notifications only landed when you refocused the app (the
+      // "notifications slow / messages don't update live" report). Off = real-time even in the tray.
+      backgroundThrottling: false,
     },
   });